Patent Document 1 discloses a vehicle underfloor structure in which an underside surface is covered with an under cover provided with a drain member. In such an underfloor structure, the underside surface is provided with recesses projecting inward, and water drain holes partly overlapped with peripheral portions on the front side of the recesses.
In the conventional underfloor structure, the water drain holes are formed into an elliptical shape elongated in a front-back direction of the vehicle, and the recesses are partly overlapped with the elliptical holes. Thus, air flowing along a bottom surface of the under cover is hardly introduced into the under cover. In other words, Patent Document 1 aims at providing the under cover including the water drain holes that hardly let water penetrate inside of the under cover.